let a=`品牌</span></td><td class='nr' width='300'><span>其他</span></td></tr><tr><td class='bt' width='130'><span>
    型号</span></td><td class='nr' width='300'><span>其他</span></td></tr><tr><td class='bt' width='130'><span>
    结构</span></td><td class='nr' width='300'><span>其他</span></td></tr><tr><td class='bt' width='130'><span>
    轴承</span></td><td class='nr' width='300'><span>其他</span></td></tr><tr><td class='bt' width='130'><span>
    风机</span></td><td class='nr' width='300'><span>其他</span></td></tr><tr><td class='bt' width='130'><span>
    最大</span></td><td class='nr' width='300'><span>其他</span></td></tr><tr><td class='bt' width='130'><span>
    叶片</span></td><td class='nr' width='300'><span>其他</span></td></tr><tr><td class='bt' width='130'><span>`
  // 替换语句
  let b=a.replace(/<\/span><\/td><\/tr><tr><td class='bt' width='130'><span>/g,"</span></td><td class='bt' width='130'><span>")
  console.log('替换前',a)
  console.log('替换后',b)